Synovitis assessed on static and dynamic contrast-enhanced magnetic resonance imaging and its association with pain in knee osteoarthritis: a cross-sectional study

Abstract Objectives To investigate the association between pain and peripatellar-synovitis on static and dynamic contrast-enhanced MRI in knee osteoarthritis. Methods In a cross-sectional setting, knee synovitis was assessed using 3-Tesla MRI and correlated with pain using the Knee injury and Osteoarthritis Outcome Score (KOOS). Synovitis was assessed in the peripatellar recesses with: i) dynamic contrast-enhanced (DCE)-MRI, using both pharmacokinetic and heuristic models, ii) contrast-enhanced (CE)-MRI, and iii) non-CE-MRI. The DCE-MRI variable IRExNvoxel was chosen as the primary variable in the analyses. Results Valid data were available in 94 persons with a mean age of 65 years, a BMI of 32.3 kg/m2 and a mean Kellgren-Lawrence grade of 2.5. IRExNvoxel showed a statically significant correlation with KOOS-Pain (r = −0.34; p = 0.001), as was the case with all DCE-variables but one. Correlations between static MRI-variables and KOOS-Pain ranged between −0.21